The proposed research concerns the synthesis of the compound sparsomycin which has exhibited potent biological activity as an anti-tumor agent in preliminary clinical tests. The compound's basis of action is the inhibition of peptide biosynthesis. The synthetic route to sparsomycin is based upon new methods for the preparation of dithioacetal S-oxides, an unusual functionality which occurs in the structure of sparsomycin. In addition to the natural product, several analogs of the drug will be prepared for biological testing. In these analogs, the pyrimidine ring, the amide linkage, the olefinic group, the hydroxy group, and the dithioacetal S-oxide moiety will be modified.